[Elecraft] KPA1500 fan noise concern

[Jim Brown]

On 5/28/2018 11:24 AM, Ralph Parker wrote:
> I ordered the '1500 In the quest to be a couple of instant db louder, 
> but if I don't hear some resolution of the noise 'problem', I'm going 
> to put the order on hold until it is solved. I do have many headsets 
> which I usually wear, including the Bose QC15 noise cancelling model, 
> but I'd hate to be FORCED into using them.

This is exactly one of the many issues that Acoustic Consultants address 
in the design of buildings that house recording studios, concert halls, 
and student practice halls in music colleges. I regularly worked with 
world-class guys in my own consulting practice, which only did sound 
system design, and I learned just enough to know that I shouldn't try to 
do their work. :)  There are many elements to the design problem, and 
the fan itself is only one of them. Other elements I'm aware of is 
turbulence of air flow, mechanical vibration coupled from the fan to the 
structure to which it is mounted, where the fan(s) are located, and so on.

I don't know if one of them was involved with Elecraft, but if not, I'd 
suggest that Elecraft buy some time from one of them. And I'd be happy 
to provide names of some good people/firms. In the early K3 days, I 
referred a good acoustics guy to Wayne to solve the problem of acoustic 
coupling between the speaker and the synthesizer that added a sideband 
to RTTY, and suggested adding the stiffener to that board solved the 
problem and became a running mod.

73, Jim K9YC